Caramelized Onion & Gruyère Strata

I’m always a sucker for a good breakfast casserole. Anything I can whip together the night before and then pop in the oven first thing in the morning? And I can easily feed a crowd with minimal effort on my part, but it’s way fancier than, say, generic Crunch Berries (I mean…organic kale and flax seed crunchy bites.)

I saw this recipe for a Caramelized Onion & Gruyère Strata in Bobby Flay’s new cookbook and it spoke to me. But it spoke louder once I contemplated adding some bacon and mushrooms, because it just feels like bacon and mushrooms belong with caramelized onions, smokey gruyère, and spinach. But if bacon doesn’t speak to you, we can’t be friends anymore. Just kidding. But really, if you don’t eat bacon or would just rather not have it, you’re perfectly fine leaving it out here and just know that’s how Bobby did it in the first place. Either way, you’re going to win all the breakfast (brunch? Brinner?) prizes. Because, you know, there is such a thing.

caramelized onion strata

If your are using bacon, cook bacon and drain and chop (this is my favorite method, and the best part is that you can leave some of the drippings in the pan and use the same pan to toast the bread). Set aside. Butter a 9×13″ baking dish and set aside.

Slice 2 large, sweet onions.

caramelized onion strata_onions

Combine 2 tablespoons of butter and 1 tablespoons of oil (I used our garlic olive oil) in a large sauté pan over medium heat. When hot, add the onions and toss to coat in the butter. Season with kosher salt and freshly ground black pepper. Cook the onion, stirring occasionally, until the onions are golden brown and caramelized. When the onions are nearly done cooking, add the mushrooms and cook until the mushrooms are tender and the onions are done. Remove from heat.

Preheat oven to 325 degrees F. Spread bread onto the baking sheet

caramelized onion strata_bread crumbs

and bake for 10 minutes, stirring once halfway through. When lightly toasted, spread the bread into the prepared baking dish. Sprinkle with bacon,

caramelized onion strata_bread crumbs and bacon

Sprinkle with 1 1/2 cups of the shredded cheese.

caramelized onion strata_mozzerella cheese

then add the mushrooms and onion mixture the drained spinach.

caramelized onion strata_mushrooms and spinach

In a large bowl, add the eggs,

caramelized onion strata_eggs

milk, cream,

caramelized onion strata_milk

mustard,

caramelized onion strata_mustard

1/2 teaspoon kosher salt,

caramelized onion strata_kosher salt

1/4 teaspoon freshly ground black pepper, and nutmeg. Whisk together and pour the mixture evenly over the bread mixture.

caramelized onion strata_pepper and nutmeg

Cover the baking dish and refrigerate for 2-24 hours.

When ready to bake, preheat oven to 350. Uncover the baking dish and bake until the mixture has puffed up and the top is golden and the strata doesn’t jiggle when you shake it (about 1 hour). During the last 10 minutes of baking, add the reserved 1/2 cup of cheese. When done, remove from the oven and allow to stand for 10 minutes before serving.

caramelized onion strata from Our Best Bites

 

To prepare the cherry tomatoes, heat the oil in a large sauté pan over medium heat. When hot, add the tomatoes, season with salt and pepper, and cook until the tomatoes begin to soften (about 5-7 minutes).

caramelized onion strata_cherry tomatoes

Remove from heat and stir in the chives. Serve on top of the strata (or alongside your favorite breakfast foods).

Use a spatula or serving spoon to dish out the casserole and then top with the sautéed cherry tomatoes.

Caramelized Onion Strata from Our Best Bites_served

 

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Caramelized Onion Strata on a plate with a fork and tomatoes

Caramelized Onion & Gruyère Strata


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Description

An elegant and delicious make-ahead meal, perfect for breakfast, brunch, or dinner!


Ingredients

  • 12 ounces bacon, cooked and chopped (option)
  • 6 cups day-old French bread or ciabatta cubes
  • 2 tablespoons butter, plus more for the baking dish
  • 1 tablespoon canola oil
  • 2 large sweet onions, halved and sliced
  • 1 cup chopped fresh mushrooms (I like baby portobellos)
  • kosher salt and freshly ground black pepper
  • 1 tablespoon fresh thyme or 1 teaspoon dried thyme
  • 2 cups grated gruyère cheese, divided
  • 1 10-ounce package frozen chopped spinach, thawed and squeezed dry
  • 10 large eggs
  • 3 cups whole milk
  • 1 cup heavy cream
  • 2 teaspoons Dijon mustard
  • 1/8 teaspoon freshly ground nutmeg
  • SAUTÉED CHERRY TOMATOES
  • 3 tablespoons olive oil
  • 2 pints cherry tomatoes
  • kosher salt and freshly ground black pepper
  • 3 tablespoons finely sliced fresh chives

Instructions

  1. If using bacon, cook bacon and drain and chop. Set aside. Butter a 9×13″ baking dish and set aside.
  2. Combine the butter and oil in a large sauté pan over medium heat. When hot, add the onions and toss to coat in the butter. Season with kosher salt and freshly ground black pepper. Cook the onion, stirring occasionally, until the onions are golden brown and caramelized. When the onions are nearly done cooking, add the mushrooms and cook until the mushrooms are tender and the onions are done. Remove from heat.
  3. Preheat oven to 325 degrees F. Spread bread onto the baking sheet and bake for 10 minutes, stirring once halfway through. When lightly toasted, spread the bread into the prepared baking dish. Sprinkle with bacon, then add the mushrooms and onion mixture the drained spinach, and 1 1/2 cups of the shredded cheese and toss to evenly distribute the ingredients.
  4. In a large bowl, whisk together the eggs, milk, cream, mustard, 1/2 teaspoon kosher salt, 1/4 teaspoon freshly ground black pepper, and nutmeg. Pour the mixture evenly over the bread mixture. Cover the baking dish and refrigerate for 2-24 hours.
  5. When ready to bake, preheat oven to 350. Uncover the baking dish and bake until the mixture has puffed up and the top is golden and the strata doesn’t jiggle when you shake it (about 1 hour). During the last 10 minutes of baking, add the reserved 1/2 cup of cheese. When done, remove from the oven and allow to stand for 10 minutes before serving. Use a spatula or serving spoon to dish out the casserole and then top with the sautéed cherry tomatoes.
  6. To prepare the cherry tomatoes, heat the oil in a large sauté pan over medium heat. When hot, add the tomatoes, season with salt and pepper, and cook until the tomatoes begin to soften (about 5-7 minutes). Remove from heat and stir in the chives. Serve on top of the strata (or alongside your favorite breakfast foods).

Notes

  • This dish was originally vegetarian and can easily be made without bacon. Also, if you cook your bacon in the oven, reserve about 1 tablespoon of the drippings from the pan and use the same pan to toast your bread–you won’t be sorry!

Nutrition

  • Serving Size: 12
Sara Wells

Meet The Author

Sara Wells

Sara Wells co-founded Our Best Bites in 2008. She is the author of three Bestselling Cook Books, Best Bites: 150 Family Favorite RecipesSavoring the Seasons with Our Best Bites, and 400 Calories or Less from Our Best Bites. Sara’s work has been featured in many local and national news outlets and publications such as Parenting MagazineBetter Homes & GardensFine CookingThe Rachel Ray Show and the New York Times.

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Questions & Reviews

  1. This looks fabulous and I can’t wait to try it this weekend. (Just a FYI, step 3 confused me and I had to read it a handful of times before I understood that the oven is only on to toast the bread, and not everything else listed on that step.)

  2. Decided to make this in lieu of my usual breakfast casserole and I’m glad I did! I think I’ve found my new Christmas morning breakfast, and the fact that it’s a make-ahead is an added bonus. I did substitute shredded gouda for the gruyere (what I had on hand), but it was still delicious. Thanks for another fabulous recipe! Merry Christmas!

  3. Looks like we are making this for Christmas morning. Thanks for a fancy breakfast dish I can make the night before. 🙂

  4. I went to your site this morning fully expecting the post to be a message about how you are taking the week off to be with your families. You should TOTALLY do that, but I’m so happy you posted this recipe first. It sounds amazing. My kids might prefer generic crunch berries, but I’m pretty sure my husband and I will hear angels singing when we bite into it on Christmas morning.